Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
74 Cards in this Set
- Front
- Back
|
what happens as a positive wave of depolarization flows towards a positive electrode?
|
there is a positive upward deflection on the EKG
|
|
|
Where does Lead 1 go? where does its positive electrode go?
|
Lead one goes on Right arm and Left arm, with the positive lead being placed on the Left Hand
|
|
|
Where does Lead 2 go? where does its positive electrode go?
|
Left Leg, right arm. with the Left Leg being the Positive electrode
|
|
|
Where does lead 3 go? where does its positive electrode go?
|
Lead 3 goes on the Left arm and Left leg, its positive lead goes on the Left foot
|
|
|
What does the aVR look at? How does the P-wave, QRS, and T appear?
|
This looks at the cavities of the ventricles
A/V depolarization moves away from the electrode- P-wave, QRS, and T-wave are all negative |
|
|
what doe aVL and aVF look at? what are the deflections like?
|
These look at the ventricles, all defections are predominantly positive
|
|
|
Where does the positive lead go in aVF?
|
this goes the Left Foot
|
|
|
where does the positive lead go in the aVR?
|
this goes on the right arm
|
|
|
where does the positive lead go in the aVL?
|
this goes on the left arm
|
|
|
What side of the heart do V1 and V2 lie over? (chest leads)
|
this lie over the right side of the heart,
|
|
|
Where do V3 and V4 lie over the heart?
(chest leads) |
These lie over the interventricular septum, with V3 being closer to the RV
and V4 being closer to the LV |
|
|
Where do V5 and V6 lie over the heart? (cheast leads)
|
these lie over the left side of the heart, so QRS is mostly positive
|
|
|
Whats the purpose of determining the net vectors from and EKG trace?
|
this is used to find the mean axis of deviation, or the mean axis of depolarization
|
|
|
What could cause a Left Axis Deviation?
|
LV hypertrophy, Pregnancy, being a fat fatty
|
|
|
What wave form are we looking at when we calculate the mean Ventricular Mean Axis of Depolarization?
|
We look at the QRS traces, on lead 1,2,3
|
|
|
What causes right axis deviation of the heart?
|
RV hypertrophy, Tall Thin body type, chronic lung disease
|
|
|
How does temperature affected the SA node?
|
an increase in temp (fever) leads to an increase in heart rate
|
|
|
What ion is related to the SA node?
|
NA
|
|
|
what ion is related to the AV node?
|
Ca
|
|
|
What ion is related to the bundle of His?
|
Na
|
|
|
What ion is related to the Bundle branches?
|
Na
|
|
|
What ion is related to the purkinje fibers?
|
Na
|
|
|
How does the rate of SA node discharge vary with Inspiration and expiration?
|
It increases with inspiration
and decreases with expiration |
|
|
What 3 tracts come off of the SA node and lead to the AV node? What other branch comes off the SA node?
|
Middle, Posterior, and Anterior Internodal tracts-
The 4th branch to come of is called Bachmann's Bundle to Left Atrium |
|
|
Does the depolarization passing through the atrial conduction system show up on an EKG?
|
No it does not
|
|
|
Where are the 3 automaticity foci located? and what are their standard pace making rates?
|
Atria- 60-80bmp
Av junction- 40-60bpm Ventricles 20-40 bpm |
|
|
What is overdrive suppression?
|
this is a failsafe mechanism of the heart, where the node with the most rapid heartbeat controls the pacing of the heart (typically SA node, then Atrial foci, then junctional foci, then ventricular foci)
|
|
|
The ventricles are completely depolarized during which isoelectric part of the EKG recording?
|
the ST segment
|
|
|
What does the P wave represent?
|
this is Atrial depolarization
|
|
|
What does the QRS complex represent?
|
this is ventricular depolarization
|
|
|
what does the T wave represent?
|
this represents the Ventricular repolarization
|
|
|
What does the duration of the P wave represent?
|
this represents the conduction time through the atria
|
|
|
What is the PR interval? What is the PR intervals Normal range??
|
This is the time from start of P wave to start of depolarization of the ventricles
NORMAL RANGE: .12-..20 seconds, normal of .16 seconds |
|
|
What does the QRS complex represent? and what is the normal time range for the QRS complex?
|
This represents the depolarization of both the ventricles (and subsequent contraction)
The duration is typically .08-.1 seconds |
|
|
What does the ST segment represent?
|
this the the plateau phase of ventricular action potential
this is an isoelectric portion of the QT interval |
|
|
What is the J-point?
|
this is where the ST segment joins the QRS complex
|
|
|
What does elevated or depressed ST segment compared to baseline indicate?
|
this indicates serious pathology
|
|
|
What causes elevation of the ST segment?
|
this is caused by Angina without exertion, or pericarditis
|
|
|
What causes depression of the ST segment?
|
This can be due to Digitalis
|
|
|
What does the T wave represent? and how long does it last?
|
This represents the later repolarization of ventricles
Lasts .16 seconds |
|
|
What does the QT interval represent?
|
this is the duration of ventircular systole (contraction)
|
|
|
What is the rule of thumb regarding heart rate and QT interval?
|
The QT interval is normal if its 1/2 the R-R interval
|
|
|
What are the upper and lower limits of the RR interval and QT interval (in seconds)
|
UPPER: RR-1.5, QT-.5
LOWER RR-.40, QT-.27 |
|
|
What does the U wave indicate?
|
This is repolarization of papillary muscle
|
|
|
On EKG paper, what size is 1 box, and what time is represented by a standard box size?
|
a standard box is 1mm square, and each millimeter equals .04 Seconds
|
|
|
How long does the QRS complex last? what does this represent?
|
.08-.1 seconds (2-2.5 boxes)
This is when ventricles are contracting/ depolarization of ventricles |
|
|
What is it called when there is no R wave?
|
a QS wave
|
|
|
What is the isoelectric point of ventricular repolarization called on an EKG?
|
the ST segment
|
|
|
What kinds of pathology can elevate the ST segment? (which is typically baseline)
|
Angina without exertion, pericarditis
|
|
|
what kind of pathology can depress the ST segment?
|
Digitalis
|
|
|
whats the standard length of the T wave?
|
.16 seconds...aka 4 boxes
|
|
|
whats the direction of the ventricular repolarization?
|
this runs from outside IN
|
|
|
What does the QT interval represent?
|
this represents the first ventricular depolarization to the last ventricular repolarization
AKA- Duration of Ventricular Systole |
|
|
Whats the rule of thumb for a normal QT rate on an EKG trace?
|
the QT interval should be 1/2 the R-R interval
|
|
|
How does the QT interval change with an increase in heart rate?
|
it will shorten
|
|
|
how does the QT length change with decrease in heart rate?
|
this will lengthen QT
|
|
|
What are the upper and lower limits for QT and RR?
|
RR-1.5, QT .5
RR .4 QT .27 |
|
|
What does the U wave represent?
|
repolarization of the papillary muscle
|
|
|
When reading EKG's what are the characteristics to look for in ST depression
|
a ST below baseline indicates Digitalis
|
|
|
When reading EKG's what are the characteristics to look for in ST elevation
|
This goes along with Angina and Pericarditis
|
|
|
When reading EKG's what are the characteristics to look for in 1st degree AV block
|
Long P-R interval (greater than .2 seconds, normal range .12-.2 sec)
Normal rate |
|
|
When reading EKG's what are the characteristics to look for in 2nd degree AV block, Mobitz 1- Wenckebach
|
Lengthening P-R interval until a dropped QRS (a P-without a QRS)
Occurs from block IN AV node Caused by Digoxin, Ca2+ blockers |
|
|
When reading EKG's what are the characteristics to look for in 2nd degree AV block, Mobitz type 2
|
regular P-R interval
Wider QRS dropped QRS not associated with change in P-P Caused by acute MI, or branch bundle damage |
|
|
When reading EKG's what are the characteristics to look for in 3rd degree AV block
|
independent atrial and ventricular rates
P not married to QRS Atria paces faster than Ventricles |
|
|
When reading EKG's what are the characteristics to look for in Atrial Flutter?
|
No P waves, Sawtooth patter,
a Ventricular rate of about 150, Atrial rate of about 300 Caused by Mitral valve disease, MI, chronic ischemia |
|
|
When reading EKG's what are the characteristics to look for in Atrial Fibrillation
|
no distinct P-waves, looks like wavy baseline. Caused by multiple atrial foci firing. 350-400bpm (atrial rate)
Irregular QRS rate caused by chronic heart disease |
|
|
When reading EKG's what are the characteristics to look for in Ventricular Fibrilation
|
Mostly flat with larger sawtooths. (looks like T de P, but without the variation in amplitude)
caused by electricution, and ischemia |
|
|
When reading EKG's what are the characteristics to look for in Wolf Parkinson White
|
This is pre excitation of the ventricules, caused by the bundle of kent.
Short P-R Delta wave (irregular or notched upstroke of the R) Wide QRS |
|
|
When reading EKG's what are the characteristics to look for in Long QT?
|
this is a long QT interval (of about 1 second?)
can lead to T de P caused by HERG K+, or SCN5A Na+ channel/genes |
|
|
When reading EKG's what are the characteristics to look for in Tosades de pointes
|
this is caused by low K+, or K+ blockers, or Long QT
Rapid ventricular rythm, that has variation in the amplitude |
|
|
When reading EKG's what are the characteristics to look for in HyperKalemia
|
This delays conduction
Tenting T waves Prolonged P-R Small flat P-waves Wide QRS (delays conduction/depolarization) |
|
|
When reading EKG's what are the characteristics to look for in Hypokalemia
|
This lengthes repolarization time
prominent U waves S-T depression Inverted T waves |
|
|
When reading EKG's what are the characteristics to look for in HypoCalcemia
|
Long QT, caused by Longer ST
|
|
|
When reading EKG's what are the characteristics to look for in Hypercalcemia
|
short ST segment, and short QT.
the T can even ride off the end of the QRS Increased calcium speeds up both ventricular Depolarization, and Repolarization |
